Electromagnetic devices fabricated from coiled magnet wire can generate significant levels of radio frequency (RF) signals when subjected to rapidly fluctuating voltages. When operating such devices in the same environment as digital and analog electronic devices such as microprocessors, radio frequency receiving and/or broadcasting equipment--such as radios and/or citizen band transmitters--such RF signals can seriously impair the performance of these digital and analog electronics. One method commonly used for suppressing RF signals from electromagnetic devices is the inclusion of a diode in the circuit of the coil or other electromagnetic device which suppresses such radio frequency signals. However, the introduction of the diode adds significant cost to and results in a relatively complex, electromagnetic device. Accordingly, what is needed in this art is a way of controlling radio frequency signals generated by electromagnetic devices, which is less complicated, more durable, less costly but yet effective.